The neurological inner workings of romantic relationships between men and women are studied for science.
| Actor | Role |
|---|---|
 Whitney CummingsJulia | Julia |
 Toby KebbellKevin | Kevin |
 Beanie FeldsteinAbby | Abby |
 Cecily StrongZoe | Zoe |
 Sofía VergaraLisa | Lisa |
 Deon ColeSteven | Steven |
 Blake GriffinGreg | Greg |
 Lucy PunchLexi | Lexi |
 James MarsdenAdam | Adam |
 Neal BrennanMarco | Marco |
 Jaylin FletcherTy | Ty |
 Adam ShapiroHank | Hank |
 Marlo ThomasLynne | Lynne |
 Adam KorsonJimmy | Jimmy |
 Kenneth LucasDave | Dave |
 Phil HendrieBill | Bill |
 Maz JobraniDoctor | Doctor |
 Jane SeymourCheryl | Cheryl |
 Will SassoDennis | Dennis |
| RRachel LaForceLindsay | Lindsay |
| VVinoj ZachariaBashir | Bashir |
 Ben PlattJoel | Joel |